The Muslim religious observance of Ashura - the 10th day of Muharram, the month that commences the Islamic lunar year - began on the evening of Sunday, November 2, 2014, and extends through Monday, November 3, by Western reckoning.

Ashura marks the death at the battle of Karbala, in Iraq in 680 CE, of Imam Husayn, grandson of Prophet Muhammad, and 72 of Husayn's followers. The first ten days of Muharram are dedicated by many Muslims, but especially by adherents of the Shia tradition, to sorrow for the tragedy of Karbala.

While Ashura is a day of grief, rather than a festival, in Turkey and among the Bektashi Muslims of the Albanian lands, fasting for Ashura is followed by consumption of a special pudding, also called Ashura, made up of grains, nuts, fruits, and sweeteners.

Some Sunni Muslims additionally participate in a fasting period of two to three days at Ashura, in which they atone for their sins. Sunni hadith - the oral sayings of Muhammad and his companions - describe the Prophet recommending imitation of the Jewish fast of Yom Kippur (the Day of Atonement) which the Prophet witnessed among Jews living in the city of Medina.

The commemoration of Ashura is central to Shia Islam. Conventional accounts of the Sunni-Shia division trace it to disagreement over the succession to Muhammad, among four caliphs, after the Prophet's death. Muhammad himself never directly designated an individual to replace him, or mentioned the concept of a caliphate. Ali Ibn Abi Talib [d. 661 CE], the son-in-law of Muhammad, was favored, it is said, by a majority of Muslims for this position. The only person born inside the Ka'bah, the sacred temple in Mecca, Ali had been the first individual to join Muhammad as a Muslim, when Ali was only 12 years old. Shias believe that Muhammad, in a hadith, identified Ali as his equal, and therefore as a candidate to succeed him. Furthermore, Ali is a powerful symbol of righteousness for the majority of spiritual Sufis, who, although they are Sunni, trace their collective lineage to him.

Imam Ali, may Allah be well-pleased with him

Yet the first of the caliphs was Abubakr [c. 573-634 CE], the father-in-law of Muhammad and parent of the Prophet's wife Aisha. A group of Muhammad's companions chose Abubakr as caliph. Abubakr died peacefully, but the next three caliphs were murdered - Umar Ibn Al-Khattab [579-644 CE], Uthman Ibn Affan [577-656 CE], and Ali.

Uthman was killed by rebels, known as the Khawarij or Karijites, from an Arabic term meaning "separatists," who called on Ali to accept their nomination of him as caliph. At first, Ali declined. The "battle of the camel" at Basra in Iraq, between the family of Uthman and the rebels, included participation by Muhammad's wife Aisha, exhorting the followers of Uthman against those of Ali. Combat was won by Ali, not least, according to Shias, because of his famous two-bladed sword. The capital of the Islamic global community, or ummah, was moved by Ali from Medina to Kufa in Iraq. His supporters were called the Shiat Ali or "party of Ali."

Ali was assassinated while at prayer in the mosque of Kufa. Shia Muslims often point out that Ali was not slain by a non-Muslim, but by a follower of Islam in a Muslim sacred place, during the holy fasting month of Ramadan. Muslims came under the rule, from Syria, of a new line of caliphs - the Umayyads, who were relatives of the third caliph, Uthman. But spreading chaos struck both the Umayyads and Ali.

With the death of Ali and entrenchment of the Umayyads, Muslims in Iraq became discontented with Syrian dominance. The Kufans were offended especially when the first distinctively Umayyad caliph, Muawiyah I [602-680 CE], was followed in the position by his own son, Yezid I [647-683 CE]. (Yezid had no connection with the unique Yezidi religious movement in Iraq.) The family of Muawiyah had opposed Muhammad at the beginning of Islamic history.

Husayn Ibn Ali was the grandson of Muhammad and son of Muhammad's daughter, Fatima. No other Muslim commanded the moral authority to defy Yezid. Husayn went from Medina to Mecca where he expressed his opposition to Yezid. The Kufans, who valued the example of Ali, appealed to Husayn to oppose Yezid by arms.

After he had set off for Kufa to rally his ostensible enthusiasts, Husayn was deserted by the Kufans, and at Karbala, Husayn, his infant son, and his soldiers were slain, with the accompanying women and children taken as captives.

Shia Muslims express repentance and bereavement on Ashura. In the first instance, because the Kufans failed to assist Husayn. In the second case, because the death of Husayn marked the loss of a figure of great rectitude and devotion - Husayn is the third imam of Shiism, after Ali and Husayn's elder brother Hasan Ibn Ali. The birthday of Ali is honored by most Shias on the 13th day of the Islamic lunar month of Rajab (May 12, 2014), and on the Persian New Year or Nevruz, at the beginning of spring, by the metaphysical Bektashis. Likewise, Ali's death on the 21st of Ramadan (July 19, 2014) is marked by Shias.

Bektashi Principles. Monument at the Harabati Baba Bektashi Teqe in Tetova, Republic of Macedonia. Photograph 2010 by the Bektashi Community of the R.M.

However much Ali is loved - and he is deeply so, among Shias - no festival of their community compares with Ashura. The martyrdom of Husayn has come to symbolize the suffering of the Shia minority within Islam at the hands of unjust Sunnis. Mourning for Husayn will continue until Arba'een, forty days after Ashura. It is common today to hear the ultra-Wahhabi terrorists of the so-called "Islamic State" compared with the lawless Khawarij who rose up against both the Umayyads and Ali. The "Islamic State" kills Shias and Sufis who honor the birthdays of Muslim holy men and women, and have sworn to destroy Husayn's tomb in Karbala as well as that of Ali, which stands in Najaf, Iraq.

Bektashis and other Shias oppressed by Sunni clerics often refer to the latter as "Yezids" - again, with no relation to the Iraqi Yezidi believers, who have been attacked by the "Islamic State." And with the proclamation of an alleged caliphate by the "Islamic State," the definition of a caliphate and how it is formed - by consensus among the Muslims or by self-proclamation - is more relevant than it has been since the Ottoman caliphate was abolished 91 years ago.

Ashura has lessons for Shias and Sunnis alike. The Kufans incited Husayn to fight Yezid and then deserted him. In a similar pattern of betrayal, Iranian and Iraqi Shia politicians have sided with the Syrian dictatorship of Bashar Al-Assad against the civic protests of its people, whose call for popular sovereignty echoes, in its way, the demands of the martyrs of Karbala. As the Umayyads massacred the followers of Ali brutally, to reinforce their unjust rule, the "Islamic State" has spread bloodshed throughout the territory it has invaded. Sectarian violence persists in Islam, and discredits the religion of Muhammad, Ali, and Husayn before the world. There is much to ponder, this year, on Ashura.